. 2023 Jul 21;6(7):e2324630. doi: 10.1001/jamanetworkopen.2023.24630

Table 3. Hazard Ratios of ASD in Offspring Associated With LEA and/or Oxytocin Exposure at Labor and Delivery, Excluding 11 473 Children With Preterm (<37 Weeks) or Postterm Birth (>42 Weeks).

Variable	No. with ASD/total	HR (95% CI)
Variable	No. with ASD/total	Model A^a	Model B^b	Model C^c
Single exposure
Epidural
No	872/48 538	1 [Reference]	1 [Reference]	1 [Reference]
Yes	3836/145 365	1.44 (1.33-1.55)	1.31 (1.22-1.42)	1.31 (1.21-1.41)
Oxytocin
No	1747/83 100	1 [Reference]	1 [Reference]	1 [Reference]
Yes	2961/110 803	1.27 (1.19-1.35)	1.14 (1.07-1.21)	1.13 (1.06-1.20)
Mutually adjusted
Epidural
No	872/48 538	1 [Reference]	1 [Reference]	1 [Reference]
Yes	3836/145 365	1.35 (1.25-1.46)	1.28 (1.18-1.39)	1.28 (1.18-1.39)
Oxytocin
No	1747/83 100	1 [Reference]	1 [Reference]	1 [Reference]
Yes	2961/110 803	1.16 (1.09-1.24)	1.06 (1.00-1.14)	1.06 (0.99-1.13)
Stratified^d
Unexposed to both	650/36 001	1 [Reference]	1 [Reference]	1 [Reference]
Exposed to oxytocin only	222/12 537	0.99 (0.85-1.16)	0.92 (0.79-1.07)	0.92 (0.78-1.07)
Exposed to epidural only	1097/47 099	1.26 (1.14-1.39)	1.21 (1.09-1.33)	1.20 (1.09-1.33)
Exposed to both	2739/98 266	1.52 (1.39-1.66)	1.33 (1.21-1.45)	1.32 (1.20-1.44)

Abbreviations: ASD, autism spectrum disorders; HR, hazard ratio; LEA, labor epidural analgesia.

^{^a}

Adjusted for birth year only; birth year was modeled as a spline function with 4 df.

^{^b}

Adjusted for birth year, maternal age at delivery, race and ethnicity, educational level, household income, marital status, parity, history of comorbidity, prepregnancy body mass index, gestational weight gain, diabetes, chronic hypertension, gestational hypertension or preeclampsia, hypothyroidism, infection, seizures, mental health issues, smoking, alcohol, drug use during pregnancy, antepartum hemorrhage, premature rupture of membranes, birth weight, preterm status, child sex, and medical center. Other than birth year, all other continuous variables were modeled as linear function and categorical variables were modeled as categorical variables.

^{^c}

Adjusted for covariates listed in note b along with birth defect, fetal distress, and dystocia.

^{^d}

Exposure stratification generated 1 variable with 4 levels: (1) unexposed, (2) exposed to oxytocin only, (3) exposed to LEA only, and (4) exposed to both LEA and oxytocin.